Set the environment variable name to value during the
execution of the rake command. You can access the value
by using ENV.

--classic-namespace (-n)

Import the Task, FileTask, and FileCreateTask into the top-level scope to
be compatible with older versions of Rake. Alternatively you can include
the line require 'rake/classic_namespace' in your Rakefile to
get the classic behavior.

--describepattern (-D)

Describe the tasks (matching optional PATTERN), then exit.

--dry-run (-n)

Do a dry run. Print the tasks invoked and executed, but do not actually
execute any of the actions.

--executecode (-e)

Execute some Ruby code and exit.

--execute-printcode (-p)

Execute some Ruby code, print the result, and exit.

--execute-continuecode (-p)

Execute some Ruby code, then continue with normal task processing.

--help (-H)

Display some help text and exit.

--libdirdirectory (-I)

Add directory to the list of directories searched for require.

--nosearch (-N)

Do not search for a Rakefile in parent directories.

--prereqs (-P)

Display a list of all tasks and their immediate prerequisites.

--quiet (-q)

Do not echo commands from FileUtils.

--rakefilefilename (-f)

Use filename as the name of the rakefile. The default rakefile
names are rakefile and Rakefile (with
rakefile taking precedence). If the rakefile is not found in
the current directory, rake will search parent directories for
a match. The directory where the Rakefile is found will become the current
directory for the actions executed in the Rakefile.

--rakelibdirrakelibdir (-R)

Auto-import any .rake files in RAKELIBDIR. (default is ‘rakelib’)

--requirename (-r)

Require name before executing the Rakefile.

--rules

Trace the rules resolution.

--silent (-s)

Like –quiet, but also suppresses the ‘in directory’ announcement.

--system (-g)

Use the system wide (global) rakefiles. The project Rakefile is ignored. By
default, the system wide rakefiles are used only if no project Rakefile is
found. On Unix-like system, the system wide rake files are located in
$HOME/.rake. On a windows system they are stored in $APPDATA/Rake.

--no-system (-G)

Use the project level Rakefile, ignoring the system-wide (global)
rakefiles.

--tasks (-T)

Display a list of the major tasks and their comments. Comments are defined
using the “desc” command.

--trace (-t)

Turn on invoke/execute tracing. Also enable full backtrace on errors.

--usage (-h)

Display a usage message and exit.

--verbose (-v)

Echo the Sys commands to standard output.

--version (-V)

Display the program version and exit.

In addition, any command line option of the form
VAR=VALUE will be added to the environment hash
ENV and may be tested in the Rakefile.